4MM = 0.15748031 of a inch
for what?Is that enough?
go down to "Options" click on "Attachments"Not sure how to post a photo.
click on "Add files" then find your photo
Seriously would stay away from this stuff, for it will separate, and unless you have it enclosed, then who knows what will happen to it, between birds and wind.
What I have looked at was a composite material, with nothing bonded to it, but still think it would produce less sound. My problem is, have not found anyone to replace yet, then again have not looked to hard either.
Not sure if posted here in this link, but neighbor put up something which was flat on inside, looked like about 2CM of insulation bonded to it. Looked like it would survive?
Whatever you do good luck.